Ignition Timing 454

[AJdoggone]

Being a prof mechanic it is hard to believe the lack of intel on this rig!!!

94' P30 454, books say to Identify timing setting by referring to code plate on firewall, well there is no plate, have looked everywhere.

Spoke with RV repair facility and they said they set timing without disconnecting the secret wire that is to be disconnected before setting timing. Degree so far has been 6-8, so I was shooting for 7 and road test and set by ear.

But to get back to that reference I need to identify what wire should be disconnected while setting. If I knew what sensor this wire goes to I could trace it to the terminal. I know I asked a few questions. Please help.

AJ

[hermanmullins]

AJ, Welcome to the Forum.

Doesn't a 94 454 have a computer? If so, can't you reprogram it to the timing you desire. Its been a long time since I heard the term "Timing by ear". I know that we used to time the old Ford Falcon 6 cylinder by ear since the Harmonic Balancer would shift on the rubber and move the timing mark. Loosen the bolt just a hair and drive, stop tap the vacuum advance and drive some more. Of course there were point and condensor too.

Check with the Mfg. of your coach, they may be able to tell you where the code is or where the wire is.

Good Luck

[C-677946]

My mechanic builds racing and boat engines and some are 454. The only way he could time my old '94 454 was by ear going down the highway. No timing plate on it to adjust the mark on the harmonic balancer with. One could make one up using top dead center and going from there, but we trusted his ear. She purred like a kitten when he got done.

[MikeCanter]

You cannot just go out and time today's motor by your ear like we used to years ago because they have a sensor that detects ping or what is called valve knock and automatically retards the motor to stop it. Used to be years ago you could advance the ignition timing until you got three pings out of the motor under acceleration in 3rd gear at 20 mph. It worked great and put the motor at the optimum point.

With today's motors you will never hear the ping because the accelerometer screwed into the motor has better hearing than you and will retard it before you hear it. So what happens is you keep advancing the ignition until you get to a point that the computer gives up then you will damage the motor. This secret wire I believe is the wire that runs to this accelerometer on the side of the engine block usually located down by the oil pan about midway back on the passenger side.

Take that plug off and now you should be able to time it by ear. Take that wire off that sensor then find a hill and if an automatic tranny accelarate lightly up the hill in third gear and listen for the valve knock. The engine needs to be at operating temps. If no knock then turn the distributor in the opposite direction of the rotation of the rotor just a small amount and try it again until you get spome valve clatter or pinging then back off on the distributor just a little until it goes away.

[dickandlois]

AJ ! 1996 is when the OBD system came into being. So your 94/454 should time up by using the number 1 plug, marking the Harmonic Balancer scribe mark with a soap stone to make it easier to see. The hard part is to get a good look at the timing mark bracket mounted on the timing chain cover because of the shroud!

The setting should be 4deg. before TDC. Forgot to mention that one needs to remove the Vacuum line going to the vacuum advance on the distributor or the timing will not set correctly. Remove and plug this line. My Bad !!! Edited 5/26/12

The timing should be the same for all big blocks 392-502.

I always checked the timing mark / setting before I moved distributor, always good to have a reference point.

Check the vacuum line to the distributor for leaks and that the counter weights are free to move under the cap.

D.M.

[Bounder1420]

I found and disconnected the wire, but I'm unsure of which timing plate to use. My 1992 454 p30 has two plates, one at 12 o'clock and one a 5 o'clock. I can't really see the upper plate but I can see the lower plate if I crawl underneath. My problem is, I can't see the mark on the harmonic balancer even after marking it with white-out. what am I doing wrong here? Should I not be using the lower plate? I dont see how it would be possible to see the upper plate because the radiator and fan is in the way. The motor runs great but I'm afraid of damaging it if I drive it.

[dickandlois]

Bounder, Welcome !! By wire do you mean the Vacuum line?

When timing the engine from the bottom marker ---3. Motor homes chassis with the timing pointer on the bottom, Bottom left side of engine looking from the front. This procedure works better with two people to set the distributor.

This requires using the #5 or #8 plug wire to trigger the time light. Check the timing mark first before setting timing, using both plugs to check the timing before proceeding.

Plug numbering Left (Drivers side) 1,3,5 and 7, Right side 2,4,6, and 8

The # 1 plug wire is used to set timing when using the top marker reference.

Taken from my post--

454 Engine Ignition Information-- Expanded

Hope this helps. Rich.